1. Field of the Invention
The invention relates to a method for calculating facial straightness and, more particularly, to a method for calculating whether a facial area in an image is straight by comparing characteristic values.
2. Description of the Related Art
With the development of the Internet, all kinds of peripheral devices are weeding through the old to bring for the new, and further they are becoming one of indispensable tools of the modern life. Video communication via a web cam can instantaneously transmit video frames to the other end of the communication, which not only makes people's communication not limited by time and space, but also provides a very convenient channel of the communication. Besides capturing the video frames, the web cam can also pick up static image, and therefore it can be used as a common tool for taking pictures.
However, the situation that a user takes a picture by himself using a web cam is different from having a professional to take a picture for him in a studio. In the studio, the professional helps to determine whether a facial angle of the user is tilted or not. When the user is taking a picture by himself using the web cam, he needs not only taking the picture and noticing the lens location simultaneously, but also confirming whether his own sitting posture is straight via the display. In this situation, it may affect the user's posture and expression that he has to notice the lens, examine the display, and operate keys at the same time. Therefore the result of taking the picture using the web cam hardly satisfies the user.
Furthermore, letting the user determine whether the picture taken is straight by himself not only time consuming but also imprecise and not objective due to the influence of the environment and his subjective sense.